Key Largo
Florida, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Key Largo, FL

A bright seascape and cloudy evening sky in Key Largo, Florida
A bright seascape and cloudy evening sky in Key Largo, Florida
Septiembre, the first month of the autumn, in Key Largo, is still a hot month, with average temperature ranging between max 89.6°F (32°C) and min 73.4°F (23°C).

Temperature

Julio through Septiembre, with an average high-temperature of 89.6°F (32°C), are the warmest months.

Rainfall

In Septiembre, the rain falls for 17 days. Throughout Septiembre, 8.39" (213mm) of precipitation is accumulated. In Key Largo, Florida, during the entire year, the rain falls for 126 days and collects up to 56.65" (1439mm) of precipitation.

Ocean temperature

In Septiembre, the average ocean temperature is 85.6°F (29.8°C).
Note: For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

Daylight

The average length of the day is 12.3h.

Sunshine

The average sunshine is 9h.

UV index

The average daily maximum UV index is 10. A UV Index reading of 8 to 10 represents a very high health vulnerability from the exposure to the Sun's UV rays for the average person.
Note: In Septiembre, the average maximum UV index of 10 translate into the following recommendations:
Take extra precautions. Fair-skinned individuals may get burned in less than 10 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What are the warmest months in Key Largo?

Julio through Septiembre, with an average high-temperature of 89.6°F (32°C), are warmest months in Key Largo, Florida.

What is the temperature in Septiembre in Key Largo?

In Key Largo, in Septiembre, the average high-temperature is 89.6°F (32°C), and the average low-temperature is 73.4°F (23°C).

How many days does it rain in Septiembre in Key Largo?

In Key Largo, Florida, during Septiembre, the rain falls for 17 days and regularly aggregates up to 8.39" (213mm) of precipitation.

What is the ocean temperature in Septiembre in Key Largo?

In Key Largo, the average seawater temperature in Septiembre is 85.6°F (29.8°C). Water temperature between 77°F (25°C) and 84.2°F (29°C) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

How many hours of daylight does Key Largo have in Septiembre?

In Key Largo, the average length of the day in Septiembre is 12.3h.

How long on average sun shines in Septiembre in Key Largo?

In Septiembre, the average sunshine is 9h.

What is the UV index reading in Septiembre in Key Largo?

The average daily maximum UV index in Septiembre in Key Largo, Florida, is 10. A UV Index of 8 to 10 symbolizes a very high hazard to health from the exposure to the Sun's UV rays.
Average temperature in September - Key Largo, FL
  • Average high temperature in September: 90°F

Warmest months (with the highest average high temperature) are July, August and September (90°F).
The month with the lowest average high temperature is January (75°F).

  • Average low temperature in September: 73°F

Months with the highest average low temperature are July, August and September (73°F).
Coldest months (with the lowest average low temperature) are January and February (57°F).

Average rainfall in September - Key Largo, FL
  • Average rainfall in September: 8.4"

The wettest month (with the highest rainfall) is June (10").
The driest month (with the lowest rainfall) is December (1.4").

Average rainfall days in September - Key Largo, FL
  • Average rainfall days in September: 17 days

Months with the highest number of rainy days are August and September (17 days).
The month with the lowest number of rainy days is April (5 days).

Average sea temperature in September - Key Largo, FL
  • Average sea temperature in September: 85.6°F

The best month for swimming (with the highest average sea temperature) is August (86.8°F).
The coldest month (with the lowest average sea temperature) is February (72.6°F).

Average daylight in September / Average sunshine in September - Key Largo, FL
  • Average daylight in September: 12.3h

The month with the longest days is June (Average daylight: 13.7h).
The month with shortest days is December (Average daylight: 10.6h).

  • Average sunshine in September: 9h

Months with most sunshine are April, May, June and July (Average sunshine: 10h).
Months with least sunshine are January, November and December (Average sunshine: 7).

Average UV index in September - Key Largo, FL
  • Average UV index in September: 10

Months with the highest UV index are April, May, June, July and August (UV index 11).
The month with the lowest UV index is December (UV index 5).